The present invention relates to a movable body control system for a vehicle which is applicable to an open/close body such as a top, a roof panel, a back window panel or a luggage panel of a convertible vehicle.
It is a known technique to arrange two motors at left and right sides and perform an open/close control of an open/close body using both motors. For example, in the open/close manipulation of a roof panel and a back window panel and the front opening manipulation of a luggage panel employed in a convertible vehicle, two motors which are arranged at left and right sides are operated and due to link mechanisms which are connected to the respective motors, the open/close manipulation of the roof panel and the back window panel and the front open/close manipulation of the luggage panel can be performed.
Japanese Patent Publication No. 2684/1991 discloses a control method of two motors for opening or closing a holding top for a vehicle. This example is provided with rotation synchronization correction means which synchronizes the rotational speeds of both motors by reducing the rotational speed of one motor out of both motors. To be more specific, in controlling these two motors, the rotational speed of one motor is reduced to the rotational speed of the other motor thereby these motor are synchronized. However, in this example, since the rotational speed of one motor is decreased so as to synchronize this rotational speed to the rotational speed of the other motor, when this control is excessively performed, it may give rise to the stop of motor.
Further, even if the excessive control may be prevented, the rotational speed cannot be restored and is held at the decreased value so that the control time may be prolonged.
On the other hand, U.S. Patent Specification No. 4087731 discloses control means of two motors for moving a large machine which cannot be moved by a single motor. In this example, present positions and present speeds of two motors, that is, left and right motors are detected and the present speeds of both motors are controlled such that the difference between a target position preset at each motor and a present position can be eliminated and the present position of each motor becomes the target position. However, in this example, the present position is made to become the preset target position by controlling the present speed, when the difference between the present position and the target position of one motor becomes extremely large as in a case where an external force is applied to either one of the motors or the like, the control of the present rotational speed of one motor must be performed in a wide scale and hence, it becomes difficult to ensure the smooth movement of the large machine.
Accordingly, it is an object of the present invention to provide an open/close body control system for a vehicle which can overcome drawbacks of the above-mentioned conventional techniques.
To solve the above-mentioned drawbacks, the present invention basically adopts technical means which calculates a target position based on positions of both motors and preset target speeds.
To be more specific, the present invention provides an open/close body control system which comprises at least two electrically-operated motors rotating a drive shaft for supporting an open/close body by way of a speed reduction mechanism, a device indicating the rotational directions of motors, rotation sensors being provided to respective motors and generating pulse signals synchronized with the rotational speeds of the motors, target speed setting means setting target speeds of respective motors, means for calculating positions and speeds of respective motors based on signals from the rotation sensors, means for calculating a target position after a lapse of a unit time based on positions and the target speeds of respective motors, means for calculating predictive positions after a lapse of a next unit time based on positions and speeds of respective motors, and synchronous control means for determining an output amount of the motors by comparing the calculated target positions with the predictive positions. In this technical means, the target positions are varied corresponding to the present positions of the motors. Accordingly, the control of the present speeds of the motors can be restricted to a small scale and hence, the smooth movement of the open/close body for a vehicle can be achieved.